Water Wars - conflics between countries for access to and control over water. global warming and populaton surplus increases this as a possibility

What is blue water?

Freshwater runoff (anything not salt water, in the hydrological cylce)

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Definitions 2

Irrigation - provision of water for crops

Cash crops - crops that can be grown and sld for money

Subsistence farming - growing only enough crops to support your family

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Living with chronic Water Shortage

Water scarcity in the Sahel

The Sahel- narrow belt of semi0arid land immeditely south of the sahara. Raifalls in only one or two onths of the year, sometimes this rain is torrential and then lost as surface runoff, causing flooding. In other years there have been several lengthy droughts.

Why is demand for water increasing?

Lots of cash crops produced - high population needs feed, water is needed for mass irrigation

The popultion is growing rapidly - Mor water will be needed for domestic purposes (e.g washing, cooking) and there are more poeple who need to be fed (cash crops) so water for irrigation as well as the demand of water for subsistence farming.

High level power consumption - Power generators need water to propel turbines and reate energy so as people use the power, the demand will become continual

Many poeple own household appliances like washing machines - Electricity is need to power the appliances, water is used to generate electricity, also sometimes the appliances use water to compete their jobs like dishwashers

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Problems of the Sahel

Social

Sustistence farmers rely on the rain to grow millet and maize

Drought or flooding could risk loss of food supplies which are critical for a growing population

Economic

Grasses die and soil erosion and desertification follow, due to overgrazing of animals- causing farming of cash crops to become impossible

Flash flooding can destroy land

Cash crop infiltration could be over done if there is excessive rainfall

Environment

Drought causes seasonal rvers to dry up and the water table to fall

Flash floods can destroy land

Drowning of crops

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Definitions 3

Eutrophication - depletion of oxygen from the water in rivers. Pollution causes the rapid growth of algea and bacteria. These require oxygen so other plants and animal lie is suffocated.

Siltation - the accumlation of silt. Can have a knock on effect further down stream.

Erosion - the wearing away of land surfaceand removal of rock by rivers, glacirs and sea.

Salinization - the accumulation of salts in the soil. Poisons land (particularly bad for dryland area beause agirculture relies on irrigation).

Irrigation - the artificial watering of crops.

Bilhazia - tropical disease caught by swimming in infested waters.

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High Aswan Dam (LEDC)

Benefits

Social - reliable source of drinking water, protects the community from famine

Human interference of water quality

Case Study, Aral Sea, over abstraction

Human Causes - cotton farming in the desert lead to the building of large scake irigation systems from the aral sea to the cotton plantation. due to careless water management by farmers, overuse of water and poor decision making about building a cotton factory in the desert, the aral sea was overabstracted.

Physical Causes - half of the water used to irrigae fields is burnt up by the sun on its journey anyway and evaporates.

Social Impacts - the bad water quality is meanin that 83% of children are being born with birth defects, people are having to migrate to find fish, food and money elsewhere, little water per day (25 mins), the spreading of typhoid disease is increasing because of pollueted water from the wells

Economial Impacts - poor crop yield, no tourist attraction, no more fishing villages, only income to the area is through the cotton farms

Other human activities affecting water quality

- Plant nutrients from fertilisers destroyed in the fields (leads to eutrophication- water deprived of oxygen by the rich nutrients)

- Organisms such as bacteria and viruses (could cause a range of disease eg cholera)

- Radioactive substances could lead to cancer

- Inorganic solid compounds such as toxic material and cyanide from mines (can poison stretches of river completely, killing all life)

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Definitions 4

Sustainable - meeting the needds of people now and in the future whilst limiting harm to the environment

Appropriate Technology - equipment that the local community is able to use relatively easily and ithout much cost

Intermediate Technology - small scale and practical solutions that local people can apply and maintain themselves

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Sustainable solutions to water crisis

The best schemes... damage the environment as little as possible, are simple and easy to run, are small scale, help the poorest people, use simple technology, help local people develop their own knowledge and skills, change local traditions as little as possible, encourage local people to work together and help themselves.